Associations between phenylthiocarbamide gene polymorphisms and cigarette smoking.

Phenotypic evidence indicates that the ability to taste the bitter compounds phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) may protect against cigarette smoking. In this study, PTC gene haplotypes were found to be associated with both the odds of being a smoker and the importance of cigarette taste as a smoking motive. Smokers (n = 384) and nonsmokers (n = 183) were genotyped for polymorphisms that affect taste sensitivity to PTC and PROP. The "taster" PAV haplotype, relative to the "nontaster" AVI haplotype, was predicted to be associated with reduced odds of being a smoker and lower taste motivation as measured by the Wisconsin Inventory of Smoking Dependence Motives-68 taste/sensory processes scale. The results did not support the predicted association between the PAV and AVI haplotypes and smoker odds, but the AAV haplotype, which confers intermediate PTC/PROP taste sensitivity, was associated with reduced smoker prevalence (49% vs. 70%), chi(2)(1, N = 567) = 10.392, p = .001. The predicted relationship between PAV and AVI and taste motivation was found, F(2, 348) = 3.303, p = .038. The results encourage further exploration of the role of taste/sensory processes in tobacco dependence.